[clang] [llvm] [AMDGPU] Introduce asyncmark/wait intrinsics (PR #173259)

[Sameer Sahasrabuddhe via cfe-commits]

ssahasra wrote:

> At a glance it looks like asyncmark/asyncwait could have been a separate patch.

And there would be no way to test them. All it would do is add unused identifiers.

> > What's missing from the overview presented by the patch description?
> 
> The new builtins like `__builtin_amdgcn_raw_ptr_buffer_load_async_lds`

That's the very first sentence of the patch description? I don't believe it's important to actually list specific instructions in the commit description.

https://github.com/llvm/llvm-project/pull/173259